US3863772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crane hoist height control
Assignee: United States Steel Corp
•
Filing: 1973-02-02
•
Granted: 1975-02-04
•
Expires: 1993-02-02
Abstract
Abstract A crane hoist height signal system has a trolley mounted grooved cable drum with a pulse generator and a tensioned constant torque spring motor mounted on the drum shaft. A cable is attached to the crane hoist block and wrapped around the drum. As the hoist block is raised or lowered, the drum rotates causing the pulse generator to send pulses to an add-subtract receiver which may be used to display block height to the crane operator or to control the crane hoist block movement.
Inventors
- 👤 George F Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:11
CPC Classifications
B; B66; B66C; B66C17/00; B66C17/06; B66C17/10; B66C13/00; B66C13/18; B66C13/46
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
A crane hoist height signal system for a crane having a hoist block comprising a cable having one end attached to the hoist block, a revolving drum mounted on the crane and attached to the other end of the cable for winding and unwinding the cable as the hoist block is raised and lowered, a shaft attached to the drum to revolve with the drum, a constant torque spring motor attached to the shaft for continuously applying a force to the drum tending to wind the cable onto the drum, a pulse generator attached to the shaft for providing a first type pulse for each predetermined increment of winding the cable and a second type pulse for each predetermined increment of unwinding the cable and means connected to said pulse generator for adding the first type pulses and subtracting the second type pulses from a predetermined total correlated with a selected hoist block height thereby providing a pulse total representative of the hoist block height.
Claim 2
Dependent Claim
165 words
A crane hoist height signal system for a crane having a hoist block comprising a cable having one end attached to the hoist block, a revolving drum mounted on the crane and attached to the other end of the cable for winding and unwinding the cable as the hoist block is raised and lowered, a shaft attached to the drum to revolve with the drum, a constant torque spring motor attached to the shaft for continuously applying a force to the drum tending to wind the cable onto the drum, a pulse generator attached to the shaft for providing a first type pulse for each predetermined increment of winding the cable and a second type pulse for each predetermined increment of unwinding the cable and means connected to said pulse generator for adding the first type pulses and subtracting the second type pulses from a predetermined total correlated with a selected hoist block height thereby providing a pulse total representative of the hoist block height.
Claim 3
Dependent Claim
29 words
A system according to claim 1 which includes means connected to said means for adding and subtracting pulses for displaying the pulse total representative of the hoist block height.
Claim 4
Dependent Claim
46 words
A system according to claim 1 which includes a crane hoist motor mounted on the crane and means connected to said motor and said means for adding and substracting pulses for controlling said motor in response to the pulse total representative of the hoist block height.
References Cited (Backward Citations)
US2752120A
Cited
US2988237A
Cited
US3119501A
Cited
US3276256A
Cited
US3406846A
Cited
US3559816A
Cited
US3750130A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |